In the United States and abroad it is current practice to install wiring, piping, ventilation and other utilities in a plenum or space above a false ceiling. This is time consuming and tedious work. As a result, workers are required to spend many hours standing on ladders or putting up staging in order to install said utilities and the hangers and wire ways needed to support such utilities. In order to overcome these expensive and laborious installations, various access floor systems have been developed.
Access floor systems generally include panels, blocks, or tray type assemblies that cover, hold, and direct the wires, ducts, and pipes that are used to deliver utilities. In addition, many such systems are constructed by the assembly of various types of individual posts, beams, brackets, and leveling systems that are used to support a top floor and to provide a space between a sub-floor and said top floor. U.S. Pat. No. 5,477,649 to Bessert is an example of one such style of construction using adjustable pedestals to support a top floor and also to support conduits and piping. U.S. Pat. No. 5,090,169 to Takeda et al. is typical of many other such systems currently in use in which plinths or pillars are used to create a space where conduits may be run between said pillars upon a sub-floor or on a tray above said sub floor. These systems can be very labor intensive to build and furthermore the space created between the floors is substantially wide open, creating the need to install additional duct work or piping and devising or providing a means of support for said duct work or piping to allow for the separation of the various utilities residing within said systems.
As a result of such difficulties, other systems have been developed in an attempt to reduce the number of different pieces that must be assembled on site in order to speed installation and ease manufacture. U.S. Pat. Nos. 5,074,085 to Ueda (1990) and 4,996,810 to Forde (1991) are two examples of this type of simplified modular access floor system. Such systems generally are constructed of arrays of interchangeable like units that limit the passage of wiring and utilities along a single plane between a top floor and a sub floor. Such panels tend to create an undesirable situation where various different types of wiring and utilities are required to overly each other and to be in close proximity or touching each other as they travel along the various passages included in such simplified modular access floor systems.
In addition, there are many access floor systems formed of metal raceways and metal access boxes designed to be used in conjunction with cement which is poured over said system after installation. U.S. Pat. Nos. 4140,791 to Kimbrough (1992) and U.S. Pat. No. 4,594,826 to Gray (1986) are typical examples of such methods. The difficulty of making changes to the layout of said access boxes after the aforementioned cement is poured and the weight of such metal raceways and said cement precludes the use of this type of system for many applications.
Finally, in the United States and abroad it is also current practice to build floor heating systems by utilizing modular, prefabricated, interconnecting, support panels. Such panels, as shown in U.S. Pat. No. 4,326,366 to Werner (1979) are used to support a floor or panels upon which a floor is laid and to allow the passage of tubing within which is carried warm or hot water. Such panels are generally formed to allow the passage of tubing only along the top or bottom surface of the panel. In addition, such panels are formed so as to prevent the passage of other objects such as wires and cables and to preclude the installation of objects such as valves, sensors, and controls.
Thus, while there are many different ways to provide utilities between a floor and sub floor, most systems do not meet all of the necessary requirements of simple design, easy installation, separation of utilities, easy access, and a means of leveling.